A security alert at the law courts in Belfast ended after a reported suspicious package was found to be a legitimate delivery.

Staff had contacted police amid fears that the item was another letter bomb.

It is understood the package that triggered the latest alert contained a number of batteries.

Police were contacted after the item was examined in a security scanner at the Royal Courts of Justice.

A PSNI spokeswoman later confirmed: "Nothing untoward was found."

Four explosive packages have been discovered in Northern Ireland in less than a week.

The latest security alert forced the evacuation of the courts in the Chichester Street area of the city centre.

Dissident republicans opposed to the peace process have been blamed for the spate of letter bombs.

Yesterday the seat of the Northern Ireland Executive at Stormont Castle was evacuated after a viable letter bomb addressed to Northern Ireland Secretary Theresa Villiers was found.

Meanwhile bomb disposal teams have made safe a viable bomb found in south Belfast.

They were called to Kilburn Street in the south of the city after the discovery of a suspicious object last night and carried out a controlled explosion.

The alerts come only 24 hours after a letter bomb was sent to Secretary of State Theresa Villiers.

The Stormont Castle headquarters of Peter Robinson and Martin McGuinness near Belfast were evacuated on Tuesday afternoon after a viable letter bomb - addressed to Ms Villiers - was intercepted.

During the alert, Mr Robinson was moved to Parliament Buildings in Stormont - his work and meetings continued unaffected.

Police later confirmed the device - discovered at around 10.30am - was a viable letter bomb similar to those found elsewhere in recent days.

Condemning the threat, Peter Robinson said "those responsible for sending this, and other devices, through the post have absolutely no regard for the lives of postal workers and staff working in offices".

Dozens of staff were evacuated during the alert, many of them also moving to Parliament Buildings.

Two letter bombs were recently sent to the police, one in Londonderry and the other to the chief constable of the Police Service of Northern Ireland. Another was posted to the Public Prosecution Service in Londonderry.